Many chronic human diseases are heterogeneous, which means that the patient population consists of different subgroups /subclasses potentially as a result of differing underlying disease mechanisms. This is further underscored by the fact that drug treatment responses vary from patient to patient with only a proportion of patients usually benefiting from a given treatment. The current ‘trial and error’ methods for treating patients is an inefficient approach to healthcare and results in significant costs to healthcare payers and often poor outcomes for patients. By analyzing the genetic or molecular profile of a patient, doctors may someday have a more rational approach to prescribing therapy, patients may respond better and the costs of healthcare may be reduced.

Because many drugs fail during clinical development due to lack of efficacy, the cost of drug development is increasing, and it is estimated that bringing a drug to market by 2010 could exceed $2 billion. (Source: Insight Pharma Reports). Success rates of clinical trials may be improved through pre-selection of patients more likely to respond positively.

The pre-selection of patients for treatment, also called personalized medicine, has been successfully applied in the areas of cardiovascular and cancer therapeutics. For example, Herceptin^®, which is prescribed to breast cancer patients testing positive for the molecular diagnostic HercepTest™, employed this approach and has subsequently gone on to generate over $1.2 billion in US sales for Genentech in 2006.

Additionally, concern is mounting over the increasing costs of prescription medicines and the risks of treating patients with pharmaceuticals who may not benefit from those drugs. Additionally, US and European regulators (the FDA and EMEA) are actively supporting the implementation of a personalized medicine approach in the development of new drugs. Because of these forces, it is widely believed that personalized medicine will play a key role in the future of medicine.